Absorbed prefixes (im-, il-, ir-) worksheets

Fifth graders sort not-words by their absorbed prefix: im- (impossible, impatient), il- (illegal, illogical), ir- (irregular, irresponsible), and learn that all three are in- shape-shifted to match the base word.

By grade

What students need to know

The prefix in- changes its skin to match the word it joins: im- before m and p (impossible), il- before l (illegal), ir- before r (irregular). Usually it means not; sometimes it means in or into (illuminate).

This skill runs from 5th grade through 6th grade. Pick a grade above for level-matched sentences, teaching notes, and worksheets.

Absorbed prefixes (im-, il-, ir-) across the grades

5th grade

Fifth graders sort not-words by their absorbed prefix: im- (impossible, impatient), il- (illegal, illogical), ir- (irregular, irresponsible), and learn that all three are in- shape-shifted to match the base word.

6th grade

Sixth graders read and spell absorbed-prefix words confidently, explain the double letters at the seam, and extend the idea to other absorbing prefixes they meet (ad-, com-).

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